The Right Mouse

Ardour is designed to work best with a three button mouse
equipped with a scroll wheel. While it can be used with a two
button mouse or touchpad, at least two key operations will not be (easily)
available:

It is strongly encouraged to invest in a three-button mouse. A good quality
mouse (especially one with a weighted, latchable scroll wheel) will make the
use of Ardour vastly more efficient. They are cheap, and time is not.